What causes the idle control speed of Audi A4 to be lower than the standard value?
1 Answers
Audi A4's idle control speed is lower than the standard value due to a dirty throttle body. Effects of a dirty throttle body: The ECU continuously adjusts the throttle opening. When the throttle body becomes excessively dirty, the ECU's adjustment reaches its limit, triggering this fault code. The throttle body needs to be cleaned, and the intake pipe should be checked for leaks. Impact of Audi A4's idle control speed being lower than the standard value: When the engine idle speed falls below or exceeds the specified range, symptoms such as intermittent stalling and unstable RPM may occur. Unstable idle manifests as engine shaking and uneven RPM during idle operation. Causes include clogged idle air jets, malfunctioning idle control devices, weak spark in individual cylinders, poor valve sealing, intake manifold leaks, incorrect ignition timing, or improper idle adjustment. Idle adjustment method: If RPM instability occurs, first adjust the idle speed. If the issue persists after adjustment, check whether the idle jet and idle air jet are clogged. If clogged, clean with gasoline or acetone and blow through with compressed air. If not clogged, stabilize the engine at a certain RPM and listen for leaks at the intake manifold or carburetor gaskets. If leaks are found, tighten screws or adjust gaskets to resolve the issue.
